Automated storage and retrieval system

ABSTRACT

There is provided an automated storage and retrieval system including: a rack storing a plurality of bins for containing items; and a transportation robot for transporting the bin in the rack. The rack includes a plurality of floors each of which stores the plurality of bins, and allows the transportation robot to run along a surface thereof, and, when the one or more bins obstructive for transportation of the target bin are arranged on the one floor, the one or more transportation robots move the one or more obstructive bins to enable another transportation robot to transport the target bin.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of priority to U.S. Provisional Application No. 63/315,563 filed on Mar. 2, 2022, and U.S. Provisional Application No. 63,482/805 filed on Feb. 2, 2023, the contents of each of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates, in general, to a warehouse system such as an Automated Storage and Retrieval System (an ASRS or an AS/RS), and more specifically, to a system to remove obstructive bins in an Automated Storage and Retrieval System.

BACKGROUND

As Electronic Commerce (EC) markets expand, improvement of item storage efficiency and item picking work efficiency for logistics has become a great problem. In order to resolve this problem, for example, WO2018/189110 A1 discloses a warehouse. This warehouse is partitioned into a storage area 10 and an order preparation area 11. Rack 100 storing trays 102 for containing storage target products are arranged in the storage area 10. On the other hand, order preparation stations 12 for operators 13 to process orders are arranged in the order preparation area 11.

Each tray 102 of the rack 100 is transported by an automated device 103. At a time of transportation, each automated device 103 takes out the tray 102 from the rack 100, and therefore the tray 102 needs to face a movement route of the automated device 103 at all times. As a result, the rack 100 employs a configuration where two rows of tray groups are stacked in a state where the tray groups including the plurality of trays 102 are aligned. According to this configuration, movement routes of the two rows of the automated devices 103 are required for two rows of tray groups at all times. It is difficult to realize improvement of efficiency for containing the trays 102 for storing products.

The present disclosure has been made in light of the above problem, and an object of the present disclosure is to provide an automated storage and retrieval system which can substantially improve efficiency for containing bins for containing items.

SUMMARY

In order to achieve the above object, according to one aspect of the present disclosure, an automated storage and retrieval system is provided, and the automated storage and retrieval system includes: a rack storing a plurality of bins for containing items; and a transportation robot for transporting the bin in the rack, wherein the rack includes a plurality of floors each of which stores the plurality of bins, and allows the transportation robot to run along a surface thereof, and when the one or more bins obstructive for transportation of the target bin are arranged on the one floor, the one or more transportation robots move the one or more obstructive bins to enable another transportation robot to transport the target bin.

The transportation robot is configured to be able to pass below the bin, and transport the bin in a state where the transportation robot lifts the bin from below.

The bin is supported on the floor by four support legs, and the transportation robot is configured to be able to enter below the bin from between a pair of the neighboring support legs.

Before the one or more transportation robots move the one or more obstructive bins, another transportation robot enters below the target bin, the one or more transportation robots move the one or more obstructive bins, and, at a same time, another transportation robot moves the target bin.

After another transportation robot moves the target bin, the one or more transportation robots arrange one of the one or more obstructive bins at a position of the target bin.

When there is a plurality of the obstructive bins, each of the plurality of obstructive bins is moved by the individual transportation robots respectively.

The floors define one or more retracted positions to which the one or more transportation robots temporarily retract the one or more bins which are the obstacles.

The automated storage and retrieval system further includes a picking station defined in the rack and used to pick the item from the bin, and the transportation robot transports the bin between the rack and the picking station, and at a non-operation time of picking work of the item at the picking station, the transportation robot rearranges the bin containing the item necessary for the picking work after start of an operation.

When the bins are rearranged in advance, the transportation robot aligns the bins to make a movement distance to the picking station shorter.

As an order of the picking work performed at the picking station after the start of the operation becomes earlier, the movement distance is set shorter.

The non-operation time of the picking work is a night time.

The bins are rearranged on the same floor as the floor on which the picking station is defined.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view schematically illustrating an external appearance of an automated storage and retrieval system 1 according to an embodiment of the present disclosure;

FIG. 2 is a plan view schematically illustrating an example of a structure of floors 11 of a rack 10 of the automated storage and retrieval system 1 according to the present embodiment;

FIG. 3 is a perspective view schematically illustrating an example of a structure of the rack 10 of the automated storage and retrieval system 1 according to the embodiment;

FIG. 4 schematically illustrates an example of a structure of a storage bin 20 of the automated storage and retrieval system 1 according to the embodiment;

FIG. 5 is a perspective view schematically illustrating an external appearance of a transportation robot 30 of the automated storage and retrieval system 1 according to the embodiment;

FIG. 6 is a side view illustrating a state where the transportation robot 30 of the automated storage and retrieval system 1 according to the embodiment lifts the storage bin 20;

FIG. 7 is a functional block diagram schematically illustrating a configuration of a management server 50;

FIG. 8 is a functional block diagram schematically illustrating a configuration of the transportation robot 30;

FIG. 9 is a side view of the rack 10 schematically illustrating an example of a configuration of a picking station 40 of the automated storage and retrieval system 1 according to the embodiment;

FIG. 10 is a plan view of the rack 10 schematically illustrating an example of a configuration of the picking station 40 of the automated storage and retrieval system 1 according to the embodiment;

FIG. 11 is a flowchart for explaining processing of a control unit 51 of the management server 50 of the automated storage and retrieval system 1 according to the embodiment;

FIG. 12 is a plan view of the floor 11 for schematically explaining transportation processing of the storage bin 20;

FIG. 13 is a plan view of the floor 11 for schematically explaining the transportation processing of the storage bin 20; and

FIG. 14 is a plan view of the floor 11 for schematically explaining the transportation processing of the storage bin 20.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. In all drawings, identical reference numerals are used to refer to identical or similar components. The following embodiment does not intend to limit the invention recited in the claims. Examples and features of the disclosed principal will be described in this description, yet can be changed and modified without departing from the idea and the scope of the disclosed embodiment. Furthermore, specific features, structures, or characteristics can be combined by an arbitrary appropriate method in one or more embodiments. The following detailed description is taken into account only as exemplary description, and the true range and idea are intended to be indicated by the claims.

FIG. 1 is a perspective view schematically illustrating an external appearance of an automated storage and retrieval system 1 according to an embodiment of the present disclosure. The automated storage and retrieval system 1 is constructed in, for example, a building 100. The building 100 includes a floor surface 101 extending along a horizontal plane, a plurality of sidewalls 102 vertically standing from the floor surface 101, and a ceiling (not illustrated) supported by the plurality of sidewalls 102. For example, the four sidewalls 102 surrounding four sides, and the ceiling extending in parallel to the floor surface 101 establish an internal space between the floor surface 101, and the sidewalls 102 and the ceiling. The automated storage and retrieval system 1 is constructed in this internal space. Note that part of the sidewalls 102 are cut out for ease of description in FIG. 1 . In the building 100, an x axis and a y axis extending in a direction perpendicular to each other on the horizontal plane, and a z axis extending in a vertical direction and perpendicular to the x axis and the y axis are defined.

The automated storage and retrieval system 1 is an automated storage and retrieval system which can automate a series of work from warehousing and storage to delivery of items including products and the like based on centralized management. The automated storage and retrieval system 1 according to the present embodiment includes a rack 10 arranged on the floor surface 101, a plurality of storage bins 20 which are containers stored in the rack 10, a plurality of transportation robots 30 for transporting the storage bins 20, one or more picking stations 40 for picking items including products and the like contained in the storage bins 20, and a management server 50 for managing the series of work of the automated storage and retrieval system 1. At the picking station 40, a human operator 60 performs picking work of picking an item from the storage bin 20.

The rack 10 includes a plurality of floors 11, each of floors 11 defining a surface which extends in parallel to each other along each xy plane, and a plurality of support columns 12 supporting the plurality of floors 11. In the present embodiment, the floors 11 of a first floor to a ninth floor vertically standing in a z axis direction from the floor surface 101 are formed. A total height of the rack 10 from the floor surface 101 in the z axis direction can be set according to a height in the z axis direction of the ceiling of the building 100. Note that part of the floors 11 of the eighth floor and the ninth floor is omitted for ease of description in FIG. 1 , and configurations of the floors 11 of the eighth floor and the ninth floor are configured similar to the floor 11 of the seventh floor.

FIG. 2 is a plan view schematically illustrating an example of a structure of the floor 11 of the rack 10 of the automated storage and retrieval system 1 according to the present embodiment. In the present embodiment, each floor 11 of the rack 10 defines a plurality of sections 13 which are aligned along the xy plane. The section 13 defines, for example, outlines of a square or a rectangle in plan view. In the present embodiment, the support columns 12 are respectively arranged at four corners of the one section 13. The one storage bin 20 occupies the one section 13. Similarly, the one transportation robot 30 occupies the one section 13. That is, an outline of the storage bin 20 and an outline of the transportation robot 30 are respectively arranged in the outline of the one section 13 in plan view. Furthermore, an interval between a pair of the mutually neighboring support columns 12 and 12 is set larger than widths of the transportation robot 30 and the storage bin 20 defined in an x axis direction and a y axis direction.

Each floor 11 defines storage areas 14 including the sections 13 in which the storage bins 20 are aligned, and movement routes 15 of the transportation robots 30 including the sections 13 other than the storage areas 14. In the present embodiment, for example, two rows of bin groups of the plurality of storage bins 20 aligned along the y axis direction are aligned in the x axis direction in the storage area 14. That is, all of the storage bins 20 making up the bin group of these two rows of the storage bins 20 face the movement routes 15 at all times. On the other hand, the transportation robots 30 can run on the movement routes 15. As described later, the transportation robot 30 can also run in the storage area 14, through a space below a bottom surface of the storage bin 20.

FIG. 3 is a perspective view schematically illustrating an example of a structure of the rack 10 of the automated storage and retrieval system 1 according to the embodiment. Referring to FIGS. 1 to 3 together, the rack 10 includes one or more transportation elevators 16. The transportation elevators 16 can make reciprocating movement in the z axis direction from the first floor to the ninth floor of the floors 11, and stop each floor 11. Each transportation elevator 16 is arranged in one section in the movement route 15 of the transportation robot 30 on each floor 11. In the present embodiment, the plurality of transportation elevators 16 may be provided to the rack 10. The transportation elevator 16 can have only the transportation robot 30 get thereon or have the transportation robot 30 holding the storage bin 20 get thereon to transport to each floor of the first floor to the ninth floor.

The transportation elevator 16 includes, for example, shafts of four corners attached to the rack 10 and extend in the z axis direction, four roller chains attached to the respective shafts, and extend in the z axis direction, four sprockets meshing with the respective chains, and two electric motors (both of which are not illustrated) for respectively rotating and driving, for example, the two sprockets. The sprockets mesh with the roller chains in response to rotation of the sprockets caused by the electric motors to ascend and descend the transportation elevator 16. Note that the support columns 12 making up the rack 10 may be used in place of the shafts. The above mechanism is a mere example, and an arbitrary another mechanism realizing vertical movement of the transportation elevator 16 may be used.

FIG. 4 schematically illustrates an example of the structure of the storage bin 20 of the automated storage and retrieval system 1 according to the embodiment. In the present embodiment, the storage bin 20 includes a bin main body 21 defining an internal space of, for example, a cuboid, and four support legs 22 extending downward from four corners of a bottom surface of the bin main body 21. The bin main body 21 includes four sidewalls 21 a surrounding four sides, an opening part 21 b opened along upper ends of the sidewalls 21 a, and a bottom surface 21 c closed along lower ends of the sidewalls 21 a. Although the opening part 21 b is opened in the present embodiment, the opening part 21 b may be closed with, for example, a lid or a cover. The sidewalls 21 a extend in parallel to, for example, the z axis. Furthermore, the bottom surface 21 c extends along the xy plane. The storage bin 20 is received on the floor 11 by the four support legs 22. The storage bin 20 may be formed by, for example, a resin material. Furthermore, the storage bin 20 may be a foldable bin. An outline of the bin main body 21 in plan view is defined as a square or a rectangle. A size of the storage bin 20 is preferably set appropriately based on a size of the rack 10 or each floor 11 or a size of an item 23.

The one or more items 23 are contained in the internal space in the bin main body 21. The item 23 can be identified by, for example, a unique Stock Keeping Unit (SKU) set to the item 23. Although the item 23 is, for example, one unit of a product or the like, the item 23 may be a so-called case product packaged in a unit of a plurality of identical products. Furthermore, the one storage bin 20 may contain only the items 23 of one type, or may contain the items 23 of a plurality of types. The storage bin 20 can be identified based on a unique ID set to each storage bin 20. The unique ID of this storage bin 20 is managed in correspondence with the SKU of the item 23 contained in the storage bin 20.

FIG. 5 is a perspective view schematically illustrating an external appearance of the transportation robot 30 of the automated storage and retrieval system 1 according to the embodiment. In the present embodiment, a plurality of the transportation robots 30 is preferably arranged on each floor 11 of the rack 10. The transportation robot 30 is, for example, an autonomous running transportation robot including a thin housing 31 of a substantially cuboid shape. The housing 31 is formed by, for example, a resin material. The transportation robot 30 can run along a line 17 (see, for example, FIG. 2 ) by tracing the line 17 drawn on the floor 11 of the rack 10 (line tracing function). The line 17 is two strips of lines which extend passing center positions of the x axis direction and the y axis direction in, for example, each section 13, and are perpendicular to each other at a center of the section 13. These lines 17 are drawn in all of the sections 13 including the storage areas 14, the movement routes 15, and the transportation elevators 16 of the floor 11.

An upper surface of the housing 31 of the transportation robot 30 extends flat along the xy plane. A height of the transportation robot 30 is set smaller than the height of the support leg 22 of the storage bin 20. Furthermore, an outline of the housing 31 in top view is defined substantially as, for example, a square. Similarly, the length of one side of the transportation robot 30 is set smaller than the length of each side of the storage bin 20. That is, the transportation robot 30 can enter the space below the bin main body 21 from between the pair of mutually neighboring support legs 22 of the storage bin 20. In this regard, the size of the transportation robot 30 is preferably set appropriately based on sizes of the rack 10, each floor 11, and the storage bin 20.

The transportation robot 30 can change the height thereof between a first configuration where the height of the upper surface of the housing 31 is set to a first height, and a second configuration where the height is set to a second height higher than the first height. As described above, the transportation robot 30 of the first configuration can enter the space below the bin main body 21 from between the pair of mutually neighboring support legs 22 of the storage bin 20. In this case, when the transportation robot 30 changes the height of the housing 31 from the first configuration to the second configuration, the transportation robot 30 holds the storage bin 20 on the upper surface of the housing 31 as illustrated in FIG. 6 . As a result, the storage bin 20 can be lifted from the floor 11. The transportation robot 30 can run in both of the first configuration and the second configuration. That is, the transportation robot 30 can run on the floor 11 while lifting the storage bin 20.

Back to FIG. 1 , in the present embodiment, the picking station 40 is established along, for example, a peripheral edge of the floor 11 which continues from the surface of the floor 11 of the rack 10. That is, the picking station 40 is established in, for example, the rack 10. In the present embodiment, for example, the two picking stations 40 are provided on the floor 11 of the second floor of the rack 10. The picking station 40 is a station for picking the item 23 from the storage bin 20 transported by the transportation robot 30 from the rack 10. The operator 60 can execute picking work (delivery work) taking a standing posture on, for example, the surface of the floor 11 of the first floor. Note that details of a configuration of the picking station 40 will be described later.

The management server 50 manages all of the rack 10, the storage bins 20, the transportation robots 30, the transportation elevators 16, and the picking stations 40 for warehousing, storage, and delivery of the automated storage and retrieval system 1. This management is realized when a program stored in a storage unit is executed by a control unit as described later. More specifically, operations and processing of the transportation robots 30, the transportation elevators 16, and the picking stations 40 are executed according to information processing described in the program. That is, the information processing described in the program functions as specific means collaborated by software in correspondence with the program, and various hardware resources of the automated storage and retrieval system 1 when the program is read by the control unit.

FIG. 7 is a functional block diagram schematically illustrating a configuration of the management server 50. As illustrated in FIG. 7 , the management server 50 includes a control unit 51 and a storage unit 52. The control unit 51 includes a communication control unit 511, a stock management unit 512, and a device control unit 513. On the other hand, the storage unit 52 stores a program 521, rack information 522, item information 523, bin information 524, and device information 525. The control unit 51 manages the automated storage and retrieval system 1 by executing the program 521 stored in the storage unit 52. This management server 50 may be realized on a physical server, yet may be realized on, for example, a cloud server.

The communication control unit 511 controls communication between the management server 50 and at least the transportation robot 30 and a terminal of the operator 60 at the picking station 40. A communication method may be, for example, Wi-Fi (registered trademark), Ethernet (registered trademark), light or the like. The stock management unit 512 manages a stock status of the automated storage and retrieval system 1. More specifically, the stock management unit 512 associates and manages information (SKU) for identifying each item 23, information related to the number of stocks of each item 23 specified based on the SKU, information (ID) for identifying the storage bin 20 in which the item 23 is stored, and information related to a position of the section 13 of the floor 11 in which the storage bin 20 is stored. Each of these pieces of information is stored as the rack information 522, the item information 523, and the bin information 524 in the storage unit 52.

The device control unit 513 manages and controls at least states and operations of the transportation robots 30 and the picking stations 40. More specifically, the device control unit 513 associates and manages information for identifying the transportation robot 30, information related to a current state of the transportation robot 30, i.e., a charging state of the transportation robot 30, information related to whether or not the transportation robot 30 engages in transportation, information related to order processing in which the transportation robot 30 engages in a case where the transportation robot 30 engages in the transportation, and information related to a current position of the transportation robot 30 at the floor 11 of the rack 10 or the picking station 40. The information related to the order processing includes, for example, information related to transportation of which item 23 of the order processing the transportation robot 30 engages in. Each of these pieces of information is stored as the device information 525 in the storage unit 52. Furthermore, the device control unit 513 associates and manages information for identifying the picking station 40, and information related to an order for which picking work is executed at the picking station 40. Each of these pieces of information is stored as the device information 525 in the storage unit 52.

Furthermore, the device control unit 513 generates commands for the transportation robot 30 and the transportation elevator 16 per order processed by the automated storage and retrieval system 1. More specifically, the device control unit 513 specifies the storage bin 20 for containing the item 23 designated by the order based on each of the above pieces of information, and specifies the transportation robot 30 which needs to be assigned to transport the storage bin 20. The device control unit 513 specifies a movement route R1 (referred to as a “robot route” below) of the transportation robot 30 to the section 13 in which the storage bin 20 is stored, and a movement route R2 (referred to as a “bin route” below) of the transportation robot 30 from the section 13 to the picking station 40 which is a destination. These pieces of generated information are transmitted as commands to the transportation robot 30 via the communication control unit 511.

FIG. 8 is a functional block diagram schematically illustrating a configuration of the transportation robot 30. As illustrated in FIG. 8 , the transportation robot 30 includes a control unit 32 and a mechanism unit 33. The control unit 32 includes a communication control unit 321, a running control unit 322, and a lifting control unit 323. The mechanism unit 33 includes a communication unit 331, a plurality of driving wheels 332, a plurality of driving motors 333, a lifting mechanism 334, a sensor 335, and a battery 336. The control unit 32 controls an operation of the transportation robot 30 by executing a program (not illustrated) stored in the storage unit (not illustrated). The program may be stored in a physical storage unit incorporated in the transportation robot 30, yet may be stored on, for example, a cloud server.

The communication unit 331 establishes communication between at least the management server 50, the transportation elevator 16, and the terminal of the operator 60 at the picking station 40. A communication method may be, for example, Wi-Fi (registered trademark), Ethernet (registered trademark), light or the like. Communication performed by the communication unit 331 is controlled by the communication control unit 321. The driving wheel 332 is a wheel for realizing running of the transportation robot 30. The plurality of driving motors 333 drive the driving wheels 332 and the lifting mechanism 334. Driving of the driving wheels 332 is controlled by the running control unit 322. The lifting mechanism 334 establishes the above-described first configuration and second configuration by lifting the housing 31 of the transportation robot 30. An operation of this lifting mechanism 334 is controlled by the lifting control unit 323.

The sensor 335 is, for example, an optical sensor for realizing the above-described line tracing function. More specifically, the sensor 335 is used to control running of the transportation robot 30 along the line 17 by reading a boundary of the line 17 drawn on each section 13. Furthermore, although the two strips of the lines 17 and 17 cross at the center of each section 13, the sensor 335 reads the line 17 perpendicular to the line 17 along which the transportation robot 30 is running, so that the transportation robot 30 can specify the center position of each section 13. Thus, the transportation robot 30 can stop at, for example, the center position of each section 13. The battery 336 is, for example, a rechargeable battery. On each floor 11 of the rack 10, one or more charging spots (not illustrated) which enable charging of the battery 336 of the transportation robot 30 may be formed.

FIG. 9 is a side view of the rack 10 schematically illustrating an example of the configuration of the picking station 40 of the automated storage and retrieval system 1 according to the embodiment. FIG. 10 is a plan view of the rack 10 schematically illustrating the example of the configuration of the picking station 40 of the automated storage and retrieval system 1 according to the embodiment. As illustrated in FIG. 9 , the picking station 40 is established along the peripheral edge of the floor 11 which continues from the surface of the floor 11 of the second floor of the rack 10. More specifically, the picking station 40 is formed on the surface of the floor 11 of the second floor which extends in, for example, the y axis direction toward an outer side of an outer peripheral edge of the floors 11 of the third floor to the ninth floor. In the present embodiment, similar to the floor 11 of the second floor, the floor 11 of the first floor also extends toward the outer side of the outer peripheral edges of the floors 11 of the third floor to the ninth floor. The operator 60 stands on the surface of the floor 11 of the first floor, and does work of picking the item 23 from the storage bin 20. The height of the surface of the floor 11 of the second floor is suitable for the operator 60 whose height is, for example, 165 cm which is an average height of adults to do the work.

As illustrated in FIG. 10 , the picking station 40 defines a plurality of picking positions 41A to 41D at which the storage bins 20 used for picking work of the item 23 are arranged on the floor 11 of the second floor. In the present embodiment, the four picking positions 41A to 41D are aligned adjacent to each other in the x axis direction along the peripheral edge of the rack 10. Each of the picking positions 41A to 41D occupies the one section 13 of the floor 11. The picking positions 41A to 41D are aligned in front of the operator 60 facing the rack 10, and the picking positions 41B and 41C of the picking positions 41A to 41D directly face the operator 60. As is apparent from FIG. 9 , no floor 11 is arranged in a space above the picking positions 41A to 41D in the z axis direction.

On the floor 11 of the second floor, for example, the two sections 13 extend toward the outer side in the y axis direction from the picking positions 41A and 41D. These four sections 13 in total define loading positions 43A to 43D at which the items 23 are loaded to shipment bins 42 which need to be shipped to clients of orders. Each of the loading positions 43A to 43D occupies the one section 13 of the floor 11. The shipment bin 42 employs the same configuration as that of the storage bin 20. According to the present embodiment, all of the loading positions 43A to 43D are aligned to a side of the operator 60 who faces the rack 10, and directly face the operator 60. Thus, as is clear from FIG. 10 , the four picking positions 41A to 41D and the four loading positions 43A to 43D are aligned surrounding the operator 60 on the floor 11 of the second floor.

Furthermore, the sections 13 further surrounding the four picking positions 41A to 41D and the four loading positions 43A to 43D define the movement route 15 of the transportation robot 30 on the floor 11 of the second floor. Although FIG. 10 omits illustration of the lines 17 for ease of description, the lines 17 are drawn in all of the sections 13 in which the four picking positions 41A to 41D and the four loading positions 43A to 43D, and the movement routes 15 are formed. Thus, as indicated by arrows in FIG. 10 , the transportation robot 30 can enter the four picking positions 41A to 41D and the four loading positions 43A to 43D from the movement routes 15. Note that the storage bin 20 is not arranged in the sections 13 forming the movement routes 15. Thus, the transportation robot 30 can transport the storage bin 20 between the storage area 14 of the rack 10 and the four picking positions 41A to 41D. On the other hand, the transportation robot 30 can transport the shipment bin 42 on which the item 23 has been loaded, to, for example, a shipping station (not illustrated) established in the rack 10.

Although the storage bins 20 are aligned on each floor 11 of the rack 10 as is apparent from FIG. 9 , the storage bins 20 for containing the items 23 of higher inventory turnover ratios are preferably aligned on the lower floors 11. In other words, the storage bins 20 for containing the items 23 of lower inventory turnover ratios are preferably aligned in the upper floors 11. In the present embodiment, the picking stations 40 are established on the floor 11 of the second floor, and therefore the items 23 of lower inventory turnover ratios are stored on the upper floors 11 for which physical movement distances of the transportation robots 30 from the second floor are assumed to be long. Similarly, the items 23 of higher inventory turnover ratios are stored on the floors 11 which are close to the second floor and to which physical movement distances are assumed to be short, or the second floor for which the transportation elevator 16 does not need to be used.

Hereinafter, delivery processing of the automated storage and retrieval system 1 according to the embodiment of the present disclosure will be described. FIG. 11 is a flowchart for explaining processing of the control unit 51 of the management server 50 of the automated storage and retrieval system 1 according to the embodiment. The operator 60 starts the delivery processing by using the terminal (not illustrated). The delivery processing starts from a time when, for example, the terminal specifies an order. The specified order includes an order line including at least SKUs and the number of the ordered items 23. The order line is displayed on a display screen of the terminal of the operator 60. Note that the terminal of the operator 60 is preferably electronic device terminals including, but not limited to, a personal computer, a smartphone, a tablet terminal, and a touch panel type display and the like.

When the delivery processing is started, the device control unit 513 specifies the storage bin 20 containing each item 23 specified by the order line (step S1). More specifically, the position of the section 13 of the floor 11 storing the storage bin 20 is specified. Specifying the positions is executed for all of the items 23 specified by the order line. On the other hand, the empty shipment bin 42 used for the specified order is arranged at one of the loading positions 43A to 43D. For this arrangement, the transportation robot 30 may be used. Furthermore, as the shipment bin 42, a container such as a shipment cardboard for an orderer may be prepared in advance. The terminal of the operator 60 is notified of the loading position 43A to 43D of the empty shipment bin 42 used for the order.

The device control unit 513 selects the transportation robot 30 which is available for transportation of the specified storage bin 20 (step S2). For example, the transportation robot 30 whose physical movement distance to the specified storage bin 20 is the shortest is selected. Note that, in addition to or instead of the physical movement distance, the transportation robot 30 which is located on the same floor 11 as the floor 11 on which the specified storage bin 20 is arranged may be selected. Next, the device control unit 513 generates the robot route R1 which is a movement route from the section 13 in which the selected transportation robot 30 is currently located to the section 13 of the specified storage bin 20, and the bin route R2 which is a movement route from the section 13 of the specified storage bin 20 to one of the picking positions 41A to 41D of the picking station 40 (step S3). The device control unit 513 transmits a transportation instruction to the selected transportation robot 30 based on the generated robot route R1 and bin route R2 (step S4).

The transportation robot 30 which has received the transportation instruction moves to the specified section 13 according to the generated robot route R1. The transportation robot 30 can transmit a use request to the transportation elevator 16 to use the transportation elevator 16. The transportation robot 30 which has moved to the specified section 13 enters the space below the bottom surface 21 c of the storage bin 20 according to the first configuration, and stops at the center of the section 13. The transportation robot 30 changes the configuration from the first configuration to the second configuration in response to driving of the lifting mechanism 334. Thus, the upper surface of the housing 31 of the transportation robot 30 lifts the storage bin 20, so that the transportation robot 30 holds the storage bin 20. Next, the transportation robot 30 moves to the specified picking positions 41A to 41D according to the generated bin route R2 while employing the second configuration. This movement may include movement performed by the transportation elevator 16.

The transportation robot 30 which has arrived at the specified picking positions 41A to 41D changes the configuration from the second configuration to the first configuration. The transportation robot 30 stays at this position until picking work of the item 23 is completed. This arrival of the transportation robot 30 is indirectly notified to the terminal of the operator 60 via, for example, the management server 50, or is directly notified to the terminal of the operator 60. This notification may be, for example, an indication on a display of the terminal, may be a notification using a voice, or may be a notification using projection mapping. Thus, the operator 60 picks the ordered item 23 from the storage bin 20 to load in the target shipment bin 42. When loading of the item 23 is completed, the operator 60 notifies the management server 50 of completion of loading via the terminal. The device control unit 513 which has received the notification transmits to the transportation robot 30 a transportation instruction for returning the storage bin 20 to the original section 13 in which the storage bin 20 has been arranged, based on the generated bin route R2 (step S5).

The transportation robot 30 which has received the transportation instruction changes the configuration from the first configuration to the second configuration, and lifts the storage bin 20. The transportation robot 30 transports the storage bin 20 to the original section 13 according to the bin route R2 while employing the second configuration. The transportation robot 30 which has arrived at the original section 13 changes the configuration from the second configuration to the first configuration. Thus, the storage bin 20 is returned to the original section 13. The transportation robot 30 notifies the management server 50 of that the storage bin 20 has been returned. The device control unit 513 which has received the notification completes the delivery processing of the item 23 (step S6). The device control unit 513 executes delivery processing of all of the items 23 listed in the order line specified by the order. This delivery processing of the plurality of items 23 is preferably executed simultaneously in parallel.

When loading of all of the items 23 listed in the order line is completed, the operator 60 notifies the management server 50 of completion of loading via the terminal. The device control unit 513 which has received the notification transmits a transportation instruction to the transportation robot 30 transporting the shipment bin 42 based on the movement route R3 (hereinafter referred to as a “shipping route”) to the shipping station (not illustrated) provided in the rack 10 (step S7). The transportation robot 30 which has received the transportation instruction changes the configuration from the first configuration to the second configuration to lift the storage bin 20. The transportation robot 30 transports the shipment bin 42 to a destination shipping station according to the bin route R2 while employing the second configuration. When completing transportation of the shipment bin 42 to the shipping station, the transportation robot 30 notifies the management server 50 of the completion. The device control unit 513 which has received the notification completes the order processing (step S8).

According to the above automated storage and retrieval system 1, the storage bin 20 which stores the item 23 specified by the order can be transported by the transportation robot 30 from the section 13 of the floor 11 of the rack 10 to the picking station 40. Mechanisms such as conveyers and operators which transport storage bins from a rack to a picking station and which are required in a conventional system are not required. Furthermore, the plurality of storage bins 20 are aligned at the plurality of picking positions 41A to 41D of the picking station 40. Consequently, the operator 60 can execute work of simultaneously picking the item 23 from each of the plurality of these storage bins 20. Efficiency of the picking work of the item 23 substantially improves. Furthermore, the storage bin 20 from which the item 23 has been picked is returned to the rack 10, so that it is possible to replace the storage bins 20 aligned at the picking positions 41A to 41D. This also contributes to making the picking work efficient.

Furthermore, the picking station 40, that is, the picking positions 41A to 41D are defined along the peripheral edge of the floor 11 which continues from the surface of the floor 11 of the second floor of the rack 10, so that the transportation robot 30 which can run on the floor 11 can easily arrive at the picking positions 41A to 41D. Furthermore, the picking stations 40 can be provided at the peripheral edge of the surface of the floor 11 of the rack 10, so that it is possible to substantially improve the degree of freedom of arrangement of the picking stations 40. In a case where, for example, in place of the operator 60, a robot arm can perform picking work of the item 23, the picking stations 40 may be provided at the peripheral edge of the surface of the upper floor 11 of the rack 10. In this case, the robot arms which can work at the picking stations 40 provided on the upper floor 11 of the rack 10 may be incorporated in the automated storage and retrieval system 1.

Furthermore, while the storage bin 20 is received on the floor 11 by the four support legs 22, the transportation robot 30 can enter the space below the bottom surface 21 c of the storage bin 20, and lift the storage bin 20. That is, the transportation robot 30 can run not only on the movement route 15 of the transportation robot 30, but also in the storage area 14 of the storage bin 20. Consequently, the degree of freedom of arrangement of the storage bins 20 on each floor 11 substantially improves.

Furthermore, the outline of the transportation robot 30 in plan view is defined on an inner side of the outline of the storage bin 20 in plan view likewise. That is, the transportation robot 30 is formed smaller than the storage bin 20 in plan view. Consequently, at, for example, the picking positions 41A to 41D of the picking station 40, the storage bin 20 can be aligned close to the neighboring storage bin 20. That is, for example, the four storage bins 20 can be aligned close to each other in front of the operator 60. Similarly, the storage bins 20 are also aligned close to each other on the rack 10, so that an arrangement density of the storage bins 20 improves.

Next, another specific example where the transportation robot 30 transports the storage bin 20 from the section 13 of the floor 11 of the rack 10 to the picking station 40 will be described below. The above-described embodiment of the present disclosure has described the example where, as illustrated in FIG. 2 , two rows of the bin groups of the plurality of storage bins 20 aligned along the y axis direction in the one storage area 14 are aligned in the x axis direction. This example is a case where the movement routes 15 of the transportation robots 30 face all of the storage bins 20. On the other hand, hereinafter, a configuration where, for example, three rows of the bin groups of the plurality of storage bins 20 are aligned in the x axis direction as illustrated in FIG. 12 will be described as an example. A scene is assumed that, at a time of, for example, order processing, a storage bin 20A in the middle row in the x axis direction among the three rows of the bin groups is transported to the picking station 40 by the transportation robot 30A. Note that, for ease of description, FIG. 12 omits illustration of the lines 17.

As is apparent from FIG. 12 , the storage bin 20A is adjacent to another storage bin 20 in, for example, both of the x axis direction and the y axis direction, that is, four sides along the xy plane are surrounded by the other storage bins 20. Hence, the storage bin 20A is arranged in the section 13 which does not face the movement route 15 of the transportation robot 30. At a time of transportation of the storage bin 20A, it is necessary to move, for example, a storage bin 20B arranged between the storage bin 20A and the movement route 15. That is, the storage bin 20B becomes an obstacle for transportation of the storage bin 20A. In this case, the device control unit 513 of the management server 50 transmits a transportation instruction which is based on the robot route R1 and the bin route R2 to the transportation robot 30A selected for transportation of the storage bin 20A. The transportation robot 30A having received the transportation instruction passes, for example, a space below the storage bin 20B from the movement route 15 according to the robot route R1, and stops in the space below the storage bin 20A.

On the other hand, prior to, at the same time as, or after transmission of the transportation instruction to the transportation robot 30A, the device control unit 513 transmits a movement instruction for moving the storage bin 20B to a transportation robot 30B selected to move the storage bin 20B. This movement instruction includes, for example, at least the robot route R1, and the movement route R3 from the section 13 in which the storage bin 20B is arranged to the section 13 which is not the obstacle for transportation of the storage bin 20A on the floor 11 on which the storage bin 20B is arranged. Details of the movement route R3 will be described later. The sections 13 which are not obstacles for transportation include, for example, the sections 13 which are not on the bin route R2 of the storage bin 20A. Note that the sections 13 which are not obstacles for transportation may be the sections 13 on the movement route 15, and may be sections 13 in the storage area 14. The transportation robot 30B having received the movement instruction enters and stops in, for example, a space below the storage bin 20B from the movement route 15 according to the robot route R1.

As illustrated in FIG. 13 , the transportation robot 30B lifts the storage bin 20B, and moves to the section 13 on the movement route 15 along the movement route R3. This section 13 is the section 13 other than the sections 13 making up the bin route R2 of the transportation robot 30A. In this regard, the bin route R2 is a route which goes from the section 13 in which the storage bin 20B is arranged to the movement route 15 in the x axis direction, then is bent toward the y axis direction, and extends as indicated by, for example, an arrow. On the other hand, the movement route R3 is a route which goes from the section 13 in which the storage bin 20B is arranged to the movement route 15 in the x axis direction, and then moves by, for example, one section to the section 13 in a direction opposite to a direction in which the bin route R2 extends in the y axis direction as indicated by, for example, an arrow. The storage bin 20B moves outside from the bin route R2 in this way, so that the transportation robot 30A can transport the storage bin 20A along the bin route R2.

The transportation robot 30A lifts the storage bin 20A, and transports the storage bin 20A toward the picking station 40 along the bin route R2. Note that the transportation robots 30A and 30B may simultaneously perform transmission and movement, or, after the transportation robot 30B moves, the transportation robot 30A may perform transportation. In the former case, for example, the device control unit 513 simultaneously transmits respectively to the transportation robots 30A and 30B instructions for executing transportation of the storage bin 20A along the bin route R2 and movement of the storage bin 20B along the movement route R3. In the latter case, for example, reception of a notification from the device control unit 513 that completion of movement of the storage bin 20B to an outside of the bin route R2 has been confirmed may trigger start of transportation of the storage bin 20A.

When confirming that the transportation robot 30A and the storage bin 20A have passed the original section 13 in which the storage bin 20B has been arranged, the transportation robot 30B executes work of returning the storage bin 20B lifted by the transportation robot 30B. More specifically, the storage bin 20B is moved not to the original section 13 in which the storage bin 20B has been arranged, but to the section 13 which is empty after the storage bin 20A is transported. Start of this work of moving the storage bin 20B may be triggered by, for example, reception of a notification from the device control unit 513 that that the transportation robot 30A transporting the storage bin 20A has passed at least the original section 13 of the storage bin 20B has been confirmed. Subsequently, the storage bin 20A from which picking work of the item 23 has been completed at the picking station 40 is returned to, for example, the section 13 in which the storage bin 20B has been stored.

In the above-described specific example, even in a case where three or more rows of the bin groups including the plurality of storage bins 20 are aligned on the floor 11, it is possible to easily transport the target storage bin 20A by using the transportation robot 30 and moving the storage bin 20B obstructive for transportation of the target storage bin 20A. As long as, for example, part of the movement route 15 of the transportation robot 30 is secured, a plurality of rows equal to or more than three rows of the storage bins 20 may be aligned. That is, as long as there is the section 13 for temporarily retracting the obstructive storage bin 20B, a minimum number of the sections 13 which need to be allocated to the movement route 15 may be set. In this way, it is possible to increase an arrangement density of the storage bins 20 on the floors 11 of the rack 10. In other words, it is possible to substantially improve containing efficiency of the storage bins 20.

Moreover, the transportation robot 30 can enter the space below the storage bin 20 from between the pair of adj acent support legs 22 of the storage bin 20, and consequently can arrive at the space below the storage bin 20A irrespectively of presence of the obstructive storage bin 20B. As a result, it is possible to simultaneously move the storage bins 20A and 20B by, for example, using the plurality of transportation robots 30, on any floor of the system. A decrease in transportation efficiency of the storage bins 20 is suppressed. Note that, in a case where, for example, there is the plurality of obstructive storage bins 20B at a time of transportation of the target storage bin 20A, it is possible to realize simultaneous movement of the storage bins 20 by using the transportation robots 30 the number of which corresponds to the number of the multiple storage bins 20B. Note that, although the one transportation robot 30 of each storage bin 20 is used in the above-described specific example, for example, the transportation robots 30 the number of which is smaller than the number of the storage bins 20 may execute the above work.

The above-described specific example has described the example where the storage bin 20B obstructive for transportation of the storage bin 20A is moved to the section 13 on the movement route 15 of the transportation robot 30. However, as illustrated in FIG. 14 , one or more retracted positions 14A to which the obstructive storage bins 20 are temporarily retracted may be provided in the section 13 outside the movement route 15 such as an inside of the storage area 14. In this example, the retracted positions 14A are defined in the one section 13 in the storage area 14 facing the movement route 15. These retracted positions 14A may be defined at, for example, predetermined intervals in the section 13 of the storage area 14 facing the movement route 15. The presence of the retracted positions 14A makes it possible to temporarily retract the storage bins 20B obstructive for transportation to the retracted positions 14A, and does not disturb movement of the other transportation robots 30 moving on the movement route 15.

Next, a scene is assumed that the operator 60 is not working on picking work of the item 23 at the picking station in the above automated storage and retrieval system 1. A non-operation time of this picking work is a night time or when human pickers (e.g. operator 60) are limited or not available. This situation is, for example, a situation that the operator 60 is not at the picking station 40, and picking work or loading work of the item 23 is not performed at the picking station 40. The management server 50 stores, for example, information related to an order to be processed in future in the storage unit 52. These pieces of information include, for example, information such as SKUs, the numbers, and the like of the items 23 per order. In this example, at a night time which is a non-operation time of picking work, work of rearranging the storage bins 20 containing the items 23 which are necessary for picking work next day is performed in the rack 10 based on, for example, information of orders which need to be processed next day.

More specifically, the one or more storage bins 20 containing the one or more items 23 which are necessary for the orders which need to be processed next day are aligned in advance near the picking station 40 at the night time. Although the picking stations 40 are formed along the peripheral edge of the floor 11 continuing from the floor 11 of the second floor as described above, the word “near” is, for example, a concept including the floor 11 of the second floor or the floors 11 such as the first floor, the third floor, and the fourth floor relatively close to the second floor. That is, the storage bin 20 is moved from the section 13 of the floor 11 arranged at this time at a night time at which picking work is finished to the section 13 of the floor 11 having a shorter movement distance to the picking station 40. Furthermore, a shorter movement distance of the storage bin 20 to the picking station 40 is set as an order of picking work of the item 23 performed at the picking station 40 after picking work is started becomes earlier next day.

According to this configuration, at a non-operation time of picking work such as a night time, for example, the storage bins 20 for which picking work is scheduled next day are aligned near the picking stations 40 in advance in the rack 10. Moreover, as the order of picking work of the item 23 becomes earlier, the storage bin 20 is aligned closer to the picking station 40. Consequently, after picking work of the item 23 starts next day, the necessary storage bin 20 is quickly and smoothly transported to the picking station 40. As a result, efficiency of the picking work substantially improves. Moreover, these series of work are executed by the transportation robots 30 based on instructions from the device control unit 513, so that work of the operator 60 is not required at all. That is, it is possible to automatically execute rearrangement work of the storage bins 20 in the automated storage and retrieval system 1. The position and movement of the bins on any floor are controlled by the robots based on instructions received from the control unit of management server.

This description discloses some embodiments of the subject matter of the present disclosure, and uses examples to enable the one of ordinary skilled in the art to carry out the embodiments of the subject matter of the present disclosure including manufacturing and using an arbitrary device and system and executing an arbitrary incorporated method. The patentable scope of the subject matter of the present disclosure is defined by the claims, and may include other examples achieved by the one of ordinary skilled in the art. These other examples intend to be within the claims in a case where the other examples include components which are not different from wordings of the claims, or in a case where the other examples include equivalent components including non-substantial differences from the wordings of the claims. 

1. An automated storage and retrieval system comprising: a rack storing a plurality of bins for containing items; and a transportation robot for transporting the bin in the rack, wherein the rack includes a plurality of floors each of which stores the plurality of bins, and allows the transportation robot to run along a surface thereof, and when the one or more bins obstructive for transportation of the target bin are arranged on the one floor, the one or more transportation robots move the one or more obstructive bins to enable another transportation robot to transport the target bin.
 2. The automated storage and retrieval system according to claim 1, wherein the transportation robot is configured to be able to pass below the bin, and transport the bin in a state where the transportation robot lifts the bin from below.
 3. The automated storage and retrieval system according to claim 2, wherein the bin is supported on the floor by four support legs, and the transportation robot is configured to be able to enter below the bin from between a pair of the neighboring support legs.
 4. The automated storage and retrieval system according to claim 2, wherein, before the one or more transportation robots move the one or more obstructive bins, another transportation robot enters below the target bin, the one or more transportation robots move the one or more obstructive bins, and, at a same time, another transportation robot moves the target bin.
 5. The automated storage and retrieval system according to claim 1, wherein, after another transportation robot moves the target bin, the one or more transportation robots arrange one of the one or more obstructive bins at a position of the target bin.
 6. The automated storage and retrieval system according to claim 1, wherein, when there is a plurality of the obstructive bins, each of the plurality of obstructive bins is moved by the individual transportation robots respectively.
 7. The automated storage and retrieval system according to claim 1, wherein the floors define one or more retracted positions to which the one or more transportation robots temporarily retract the one or more bins which are the obstacles.
 8. The automated storage and retrieval system according to claim 1, further comprising a picking station defined in the rack and used to pick the item from the bin, wherein the transportation robot transports the bin between the rack and the picking station, and at a non-operation time of picking work of the item at the picking station, the transportation robot rearranges the bin containing the item necessary for the picking work after start of an operation.
 9. The automated storage and retrieval system according to claim 8, wherein, when the bins are rearranged in advance, the transportation robot aligns the bins to make a movement distance to the picking station shorter.
 10. The automated storage and retrieval system according to claim 9, wherein, as an order of the picking work performed at the picking station after the start of the operation becomes earlier, the movement distance is set shorter.
 11. The automated storage and retrieval system according to claim 8, wherein the non-operation time of the picking work is a night time.
 12. The automated storage and retrieval system according to claim 8, wherein the bins are rearranged on the same floor as the floor on which the picking station is defined. 